BIOL 103 Home

Biomorph Challenge #3

Water, Air, and Energy
Type, print out, and turn in BEFORE class.
10 points off for late work.
10 points off for lack of staple.

1. The Biomorphs keep trying to pull the wool over our eyes:

"Our advanced Biomorph technology will require only 1.5 x 1014 kilowatts of power. We'll obtain this on Earth with solar energy."

How do you respond to this challenge? Use a calculation to counter the Biomorph claim. (Hint: Facts below may be useful.)

Facts about Water and Energy

Water accounts for 60% of our total weight
Density = 1 g/ml
Water disposal
            Respiration = 0.5 liter per day
            Sweating and transpiration = 0.9 liter per day, more in hot weather
            Urine = 1.5 liter per day
            Feces = 0.1 liter per day

Water consumption
            Drinking water = 1.5 liter per day
            Water in food = 0.9 liter per day
            Water produced during the metabolism of food = 0.6 liter per day

Water use
            Saliva = l liter per day
            Gastric juice = 2 to 2.5 liter per day
            Bile = 0.5 liter per day
            Pancreatic juice = 0.7 liter per day
            Intestinal secretion = 3 liter per day
            Blood contains 3 to 4 liter of water
Global water     
            Ocean covers 70% of Earth's surface
Solar power
            Average power available from sunlight on Earth (day and night) = 300 Watts per m2
            (0.3 kilowatts per square meter) = 300 Joules/second m2
            Earth's surface area = 5.1 x 108 km2 (square kilometers)

Useful conversions:

1 kg = 2.2 pounds
Watt = Joules per second; W = J/sec
1 ( km)2 = (103 m)2 = 106 m2

 

2. Use your graph of water saturation and temperature to solve these problems. Suppose that a front of air containing 0.7% water vapor blows over Gambier.

(a) What happens if the air cools to 10°F? What is now the relative humidity?

 

(b) Inside your dorm, the air is heated to 65°F. What is now the relative humidity? What effect does it have on the human body?

 

3.  A camel can lose 30% of its weight in water after 17 days in the desert without drinking; then, when it finds water, it can drink enough in ten minutes to replace it all. Suppose after 17 days in the desert a fully dehydrated camel weighing 500 kg finds water; how much would it have to drink?
What would be its final weight after drinking?

 

4.  A stillsuit is used on Dune to conserve water. 

 

(a) Explain the function and the problems to be overcome in designing a stillsuit.

 

(b) How much water is lost through human wastes? In a stillsuit, what happens to these wastes? What is the consequence for Fremen society; what's it like to be in a cave with a lot of Fremen?

 

5.  Suppose solar energy is used on this planet.  Assume the facts listed above.

 

(a) Today, the best photovoltaic solar panels are able to convert 20% of the available energy to electricity.  If a glowglobe uses as much electricity as a 25 Watt light bulb, how large an area of solar panels would be needed to light one glowglobe for each of the 1000 persons living in the sietch? 

 

(b)  Suppose a "plantoid" alien being uses photosynthesis (with 20% solar efficiency) instead of eating food. Assume a human being eats food containing 2000 food Calories per day (1 food Calorie = 4.18 kilo-Joules). What surface area (in square meters, m2) would the plantoid need to sustain itself?

 

6. In human technology, the overall per capita power consumption (and the waste products of fuel) are increasing.

 

(a) Today in the United States, the per capita power consumption is 10,500 Watts. In Bangladesh, it is 265 Watts. For the Bangladeshi per capita power to grow exponentially to reach that of the United states by 2100 (assuming that of the U.S. remains constant) what doubling time would be needed?

 

(b) In the year 1960, the CO2 level in Earth's atmosphere was 317 parts per million (ppm). In 2000, the CO2 level was 370 ppm. If CO2 increases exponentially, what is the doubling time?

 

7. Compare and contrast the ecosystems of Gambier and of Dune.

 

(a) How do materials and energy cycle in each ecosystem?

 

(b) What is lacking or incomplete about the Dune ecosystem?